Page 93 - swp0000.dvi
P. 93

where



                                                                 µ               ¶
                                                                   1
                                                                       2
                                              =    +    −    Θ   +  0 
                                                                   2
                       The amplitude  and the width ∆ are given by
                                           0
                                                                          r
                                                       3                  8
                                                 =           and ∆ =                                 (4.13)
                                                 0         2
                                                      2                  

                   with


                                                           2
                                                      =  +   2   0  − 1                          (4.14)
                                                           
                                                                  
                    0 is an arbitrary constant,   and   are the direction cosines of the wave

                   propagation with the  and  axes, respectively, and fulfill the condition
                                                                        2
                    +  =1 Also note that the product  ∆ =12  is independent of
                                                                                2
                     2
                          2
                                                                   0          
                    0 but depends on .

                   4.3      Results and Discussion



                     Dust acoustic soliton features in an unmagnetized dusty plasma having
                   Boltzmann distributed electrons, nonthermal ions, cold and hot adiabatic

                   dust grains have been studied. The application of the reductive perturba-

                   tion theory to the basic dust fluid equations leads to a nonlinear 3D-CKP
                   equation (4.11). In this study, the gravity force is neglected, on assuming

                   the dust radius    1 The mathematical results applied in F rings of

                   Saturn under the conditions: (i)   is smaller than 1, (ii) there are no
                   neutrals, (iii) the coupling parameter Γ  is less than unity, and (iv) the

                   ratio of inter-grain distances to Debye radius is less than one. Numerical

                   values corresponding to F-rings of Saturn have been used; the equilib-

                   rium dust and electron densities are  0 =10   0 =10   and dust
                                                                                              −3
                                                                              −3

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